Answer:
The phrase that is an infinitive is to read in sentence C. Shane said his favourite thing to read is mysteries.
Step-by-step explanation:
Infinitive phrases are groups of words that use the construct to+simple form of the verb. These phrases may include modifiers and can function as nouns, adjectives or adverbs. One must pay attention to the difference between the preposition to -that is followed by a noun construction, like sentences A, B and D- and to as part of the infinitive -followed by a verb.